This was a fun project, while it lasted. Except, it lasted only three months. In this time we got the 4-rotor contraption to take off, and hover relatively stably above ground. However, the Hoverbot was confined in x and y direction by a support fixture (see inset in the illustration above, which shows the Hoverbot during stable hovering). Yaw, pitch, roll, and elevation (motion in the z-direction) were controlled and stabilized by the computer.
The reason for discontinuation of the project was the sponsor's stopping of financial support. We accepted that cut with grace, because the project was an experimenter's nightmare: For example, the rotary wings on the four rotor heads had to be hand-crafted from balsa wood, because one cannot buy rotary wings for both cw and ccw direction. Consequently, the rotary wings were difficult to balance, causing serious vibration problems. There were many more experimental difficulties, but I don't want to go into all those.
Still interested? There is an annual "Aerial Robot Competition." One contact is: firstname.lastname@example.org. Some video footage on these contests can be obtained from Future Watch
Program 44, #2 Air Date: June 20 1992Library Tape Sales One CNN Center P.O. Box 105366 Atlanta, Georgia 30348-5366 Tel. (404) 827-1500
If you would like to get good documentation on the 1991 event (the first year that the competition was held), you can get a tape (I don't know if there is a charge) from:Scientific American Frontiers Program 202 "Aerial Robots" c/o The Chedd-Angier Production Company 70 Coolidge Hill Road Watertown, MA 02172 Tel. (617) 926-8300